Method and system for connecting subscribers of a telecommunication network in a switching center

ABSTRACT

A method and system for connecting subscribers of a telecommunication network in a switching center which includes an input for receiving signaled data, a means for forming and processing connection-related data from the data received at the input side, and a means for signaling the processed data at the output thereof, wherein there is provided a means for the conversion of connection-related data into neutral parameters with the aid of a predetermined parameter list, a means for processing there neutral parameters independent of the original format of the connection-related data, and a means for the back-conversion of the processed neutral parameters into connection-related data with the aid of the parameter list in order to send these back-converted data to the output after a neutral evaluation or, respectively, modification.

BACKGROUND OF THE INVENTION

The present invention relates to a method and a system for connectingsubscribers of a telecommunication network in a switching center thatincludes an input for receiving signaled data, a means for forming andprocessing connection-related data from the data received at the inputside, and a means for signaling the processed data at the outputthereof.

Due to the modernization of telecommunication networks, new signalingmethods (analog, digital, ISDN) and the addition of available servicesin a switching center result in more expensive connection control. Whereearlier a simple switching through of subscriber A to subscriber B onthe basis of the selected call number was sufficient, now more and moreinformation has to be taken into account when a call is switchedthrough; e.g., the category of the call (telephone, fax, modem), thedesired network operator, bearer capabilities (quality and data rate ofthe operator), category of the subscriber, etc. In the course ofconnection control, it is now necessary with increasing frequency toevaluate the data received at the outset, according to particularcriteria, and to modify it if warranted.

In known apparatuses, the sequence program of the connection controlmust be modified correspondingly in order to enable the use of newservices or information; i.e., the logic for evaluation and modificationof connection-related data must be fundamentally reprogrammed. However,this is connected with a considerable expense that results in high costsfor the network operator. In addition, errors can occur duringreprogramming of the connection control which can lead to lastingproblems.

From EP-0 540 256 A2, an arrangement is known for call handling in aswitching means, in particular for the maximally flexible management ofnumbering plans of different communication networks. An adaptation of anexisting switching means, given modifications or expansions of thenumbering plan originally supported by it, is avoided by grammaticallyanalyzing the numbers of the communication network according to thenumbering plan, in the manner of a language in themathematical/information-technological sense. Data structuresindependent of the numbering plan are thereby used for the determinationof the call-related numerals and services. Thus, symbol strings arereceived whose contents are determined by the application of syntax andgrammar according to the stored data structures, and a handling of thecall is defined independent of the respective numbering plan. Thedependencies of the switching means on the supported numbering plan arespecified solely by the content of the data structures, so that formodifications or expansions of the already-existing numbering plan onlycorresponding adaptations of the definitions in the data structures areto be carried out. In this way, it is possible for the switching meansto be able to implement any numbering plan by means of the arrangementfor call handling.

From EP-0 557 645 A2, a method is known for the external calling ofperformance features of a switching means that includes an internalnumbering plan in a communication network with an associated networknumbering plan. A call processing means of the switching means therebyuses stored information such as syntax and grammar of the respectivenumbering plans. The switching means receives a call-related symbolsequence and interprets it as an equivalent access code of a performancefeature, and subsequently calls it.

From the article “Schema translation into a unified model for serviceoperation,” a model is known for service handling in which a mutualcommunication of processing systems becomes possible by translation ofthe respective individual local schema into a unified schema. From thearticle “Mapping strategies for a relational view of the No. 1A ESStranslations data base,” a method is known for the imaging, for modelingpurposes, of a complex database for the example of a switching means.This database is constructed in structured form for a maximallyeffective call handling and storing of the data. The model creates anindirect interface to the database in order to apply a preceding orsubsequent strategy for the management of the database accesses.

From U.S. Pat. No. 5,416,835, a method is known for the automaticidentification of the type of signaling used on the basis of a call forthe setup of a connection to a central switching means. Detectors fordetermining whether a two-tone multifrequent signaling is present arethereby arranged in the vicinity of the switching means. From U.S. Pat.No. 4,914,690 a universal interface is known between a private branchexchange and a central switching means, which enables support even oftelephone installations that are not compatible with the private branchexchange, by means of standardized conversion.

It is therefore an object of the present invention to create a methodand a system for processing connection-related data that is asindependent as possible of the individual signaling methods and that canbe adapted easily and economically.

SUMMARY OF THE INVENTION

This object is inventively solved in a method and system wherein, bymeans of a predetermined allocation with the aid of a predeterminedparameter list, the connection-related data is converted into neutralparameters independent of the original format of the data. Theseparameters are then processed in their neutral format by the switchingcenter. Thereafter, the data to be signaled at the output side is formedfrom the neutral parameters by means of the predetermined allocation,with the aid of the parameter list, by means of back-conversion.

According to the present invention, a system for the solution of theabove-stated object includes a means for converting connection-relateddata into neutral parameters with the aid of a predetermined parameterlist, a means for processing these neutral parameters independent of theoriginal format of the connection-related data, and a means forconversion of the processed neutral parameters back intoconnection-related data with the aid of the parameter list; these backconverted data being sent at the output of the switching center forconnection controlling. For the processing of the neutral parameters, adata revaluing unit and a data modification unit are provided whereinthe data revaluing unit is set up so as to evaluate the data received atthe input side after conversion into neutral parameters, and the datamodification unit is set up to modify the neutral parameters which areeither dependent on the result of the evaluation by the data revaluingunit or dependent on the result of the allocation by the conversionmeans, or dependent on output-side control parameters. By means of this“neutralization” of the connection-related data independent of thesignaling method or, respectively, of the format and definition of thisdata, the evaluation and modification of the data can be executed inuniform fashion for all signaling methods and data formats.

Given the addition of new signaling methods or new services, it is oftensufficient to add particular entries to the parameter list in order toensure orderly allocation of newly incoming connection-related data intoneutral parameters, wherein the evaluation thereof and back-conversionthereof is into format-dependent data. The sequence program of the dataevaluation and modification accordingly remains unmodified so that insuch cases the expense for adapting a switching center can be loweredconsiderably.

In a preferred embodiment of the inventive method, it is provided thateach neutral parameter is formed dependent on the signaling method used,such as TUP, ISUP, MFC-R2, whereby a corresponding parameter set isdefined in the parameter list for each allowed signaling method. Inaddition, in this embodiment it is useful to define for each parameterof the parameter list a particular data format and a particular valuerange.

Given the use of a digital transmission protocol for central signalingchannels (CCS=Common Channel Signaling), such as ISUP, TUP, GSM, theconnection-related data is that which is defined in the varioussignaling methods as messages serving for the connection setup(mandatory and optional messages) or, respectively, message contents;e.g., the entries of the initial address message (IAM) or, sequentialaddress message (SAM) of an ISUP transmission protocol. Each message or,respectively, each individual message part, e.g., each entry of the ISUPmessage (IAM, SAM), is converted with the aid of the parameter list intoa respective modification unit. After an evaluation by the datarevaluing unit, the neutral parameters of the connection-related datacan be modified dependent on this evaluation by means of a datamodification unit. Alternatively, the neutral parameters of theconnection-related data can be modified by a data modification unitalready before their processing by the data revaluing unit, dependent onthe result of the data allocation. It is likewise possible tosubsequently modify the neutral parameters dependent on output-sidecontrol conditions. By this means, a maximally flexible evaluation or,respectively, modification of the data in their neutral format ispossible.

Additional features and advantages of the present invention aredescribed in, and will be apparent from, the following DetailedDescription of the Invention and the Drawings.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 shows a schematic diagram of the method and system of the presentinvention; and

FIG. 2 is a schematic representation of the connection control methodand system of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

In order to switch through calls from a subscriber A to a subscriber B,corresponding inputs and outputs are provided in a switching center,combined with one another via a connection control. The terminals can beof various types; e.g., individual terminals, private branch exchanges,mobile terminals, terminals for connecting lines and terminals fordatabases and/or monitoring computers. These terminals can be occupiedin analog or digital fashion wherein, in principle, various protocolvariants, such as ISUP, TUP, ISDN, GSM, DECT, etc., are available,especially for digital terminals.

For all existing terminals, terminal-related data required by theswitching center for connection controlling is stored in the switchingcenter. In FIG. 2, the terminal-related data is designated DATA A; DATAB and wherein A designates the terminal data of the input-side terminaland B designates the data of the output-side terminal.

If a signal is received by the switching center at one of the inputs,the data transmitted in this signal must be transposed into a neutralformat. This data allocation is executed by means of a logic unit DZO A,which has access both to the allocated terminal-related data DATA A andto a parameter list PARAMETER in which the allocation regulations forthe conversion of format-related data into neutral parameters arestored. In the parameter list, a certain number of possible parametersare defined, e.g. PAR1, PAR2, PAR3, . . . , PAR256, whereby a set ofallocation regulations is predetermined for each parameter dependent onthe possible signalings.

For connection control by means of the switching center, in digitaltransmission methods a particular message is sent on central signalingchannels (CCS) =Common Channel Signaling); namely, an Initial AddressMessage (IAM) or, if warranted, additional messages called SequentialAddress Messages (SAM). In these messages, particular data is stored inindividual entries which is relevant for the connection control (e.g.,category of the A subscriber), call number of the A and B subscriber,desired service (voice, fax, modem), etc. In the context of the presentinvention, it has proven advantageous to define a particular parameterfor each of the possible entries of an IAM or SAM; e.g., a respectiveparameter for the call number of the A and B subscriber, a respectiveparameter for the desired service, a respective parameter for thecategory of the A subscriber, etc.

In the allocation by means of the logic unit DZO A, each of theparameters required for the connection control is allocated an abstractvalue; e.g., a numerical value or a string. The allocation is dependenton the signaling method used, so that a particular parameter definitionis present for each supported signaling method and for each parameter ofthe parameter list PART, . . . , PAR256. In addition, in the parameterdefinition it is defined whether the entry is located in an IAM or anSAM (message ID). In order to check the allocation, indications of theresult to be expected also can be contained in the parameter definition;e.g., a value range, a number of digits, or the like. If individualparameters are not supported by a signaling method (e.g., given analogsignaling), these parameters can be set, to default values by means ofthe data allocation logic unit DZO-A, in case they are required later.If warranted, the default values can also be produced during the laterevaluation and modification of the neutral parameters.

The neutral parameters formed by the data allocation logic unit DZO-Aare now further processed by means of a data revaluing unit UMW. In thisdata revaluing unit UMW a uniform sequence program is installed for theevaluation of the neutral parameters, in order to obtain from theseneutral parameters a result that is relevant for the connection control.

If the evaluation yields the result that another modification of certainparameters is required for a successful connection setup, a datamodification unit MOD is driven for this purpose which modifies thesupplied parameters corresponding to requirements. The result of themodification is typically handed over again to the data revaluing unitUMW for new evaluation of the modified parameters.

If warranted, the requirement of a modification of individual neutralparameters also can be defined by means of the data allocation logicunit DZO A. In this case, the data modification unit MOD can becontrolled directly by the data allocation logic DZO A.

After an evaluation and, if warranted, a modification of the neutralparameters of the connection control, these parameters are handed overto a data allocation unit DZO B which, with the aid of the parameterlist and the terminal related data DATA B, produces the format-relateddata for the signal to be sent; e.g., a new IAM or SAM, which issubsequently sent to the relevant output.

If warranted, the requirement of a subsequent evaluation or modificationof individual connection-related data can be forced by B-side terminalconditions or control conditions. In this case, the terminal data orcontrol data DATA B required for the modification can be transposed intoa neutral format using the data allocation logic unit DZO A, andprocessed correspondingly by means of the data revaluing unit UMW anddata modification unit MOD.

Although the present invention has been described with reference tospecific embodiments, those of skill in the art will recognize thatchanges may be made thereto without departing from the spirit and scopeof the invention as set forth in the hereafter appended claims.

I claim:
 1. A method for connecting subscribers of a telecommunicationnetwork, wherein connection-related data is processed independent from asignaling method of signaled input data received by a switching center,the method comprising the steps of: receiving signaled input data at aninput side of the switching center; forming connection-related data fromthe input data; converting the connection-related data into neutralformat parameters independent of an original format of theconnection-related data via a predetermined allocation using apredetermined parameter list; processing the neutral format parametersby the switching center; and forming output data to be signaled at anoutput side of the switching center from the neutral format parametersby back-conversion via the predetermined allocation using apredetermined parameter list.
 2. A method for connecting subscribers ofa telecommunication network as claimed in claim 1, further comprisingthe steps of: forming each neutral format parameter dependent on thesignaling method used; and storing a corresponding parameter set in theparameter list for each signaling method used.
 3. A method forconnecting subscribers of a telecommunication network as claimed inclaim 2, further comprising the step of: defining both a particular dataformat and a particular value range for each parameter of the parameterlist.
 4. A method for connecting subscribers of a telecommunicationnetwork as claimed in claim 1, further comprising the steps of: definingthe connection-related data as that which is defined in the signalingmethods as one of messages and message contents serving for a connectionsetup; and converting the connection-related data, using the parameterlist, into a respective neutral format parameter for further processingvia a data revaluing and data modification unit.
 5. A method forconnecting subscribers of a telecommunication network as claimed inclaim 4, further comprising the step of: modifying the neutral formatparameters of the connection-related data by the data modification unitafter their evaluation by the data revaluing unit wherein themodification is dependent on the evaluation.
 6. A method for, connectingsubscribers of a telecommunication network as claimed in claim 4,further comprising the step of: modifying the neutral format parametersof the connection-related data by the data modification unit beforetheir processing by the data revaluing unit, wherein the modification isdependent on a result of the data allocation.
 7. A method for connectingsubscribers of a telecommunication network as claimed in claim 4,further comprising the step of: modifying the neutral format parameters,after their evaluation and modification, dependent on output-sidecontrol parameters.
 8. A system for connecting subscribers of atelecommunication network in a switching center, whereinconnection-related data is processed independent from a signaling methodof signaled input data received by the switching center, comprising: aninput for receiving signaled input data; a means for forming andprocessing connection-related data from the input data; a means forconversion of the connection-related data into neutral format parametersusing a predetermined parameter list; a means for processing the neutralformat parameters independent of an original format of theconnection-related data; a means for back-conversion of the processedneutral format parameters into connection-related data using theparameter list; and an output for outputting the back-convertedconnection-related data.
 9. A system for connecting subscribers of atelecommunication network in a switching center as claimed in claim 8,further comprising: a data revaluing unit, wherein the data revaluingunit evaluates the input data after the conversion thereof into neutralformat parameters; and a data modification unit, wherein the datamodification unit modifies the neutral format parameters dependent onone of the result of the evaluation by the data revaluing unit and theresult of the allocation by the means for conversion.